The following are excerpts from an article by Saint Innocent Bishop of Alaska, The Way into the Kingdom of Heaven.
The road into the Kingdom of Heaven was made by the Lord Jesus Christ, and He was the first one who travelled it. The Bible teaches that only he who follows Jesus can reach His Kingdom. But how can one follow Him? Hear what our Savior says about this: Whoever desires to come after Me, let him deny himself, and take up his cross, and follow Me (Mark 8:34).
1. First of all, a Christian must thoroughly study the foundations of the Christian faith.
2. When you become convinced that our Orthodox faith is based on Holy Scriptures and is not invented by people and that the Holy Scriptures contain the true word of God, revealed by the Holy Spirit through prophets and apostles — accept it with all your trusting heart.
3. Finally, try to nourish a diligence in yourself to follow that which is taught by the Holy Scriptures.
To reach the Kingdom of Heaven, we should determine which path leads to it, how not to falter, what we must beware of, etc. Our map is the Holy Scriptures and other Orthodox books; the rangers are the pastors of the Church, whose duty it is to help the faithful on their way toward Paradise. The provisions are the Mysteries (Sacraments) of the Church, which reinforce our spiritual strength. Sometimes the path leading to Paradise may become narrow, steep and overgrown with bushes, whereas other paths may seem wider and easier to travel. It is very important not to stray from the correct path. The Lord Jesus Christ and His Apostles repeatedly warned that there is but one path that leads to the Kingdom of Heaven, the one given in the Gospel. All others, especially the wide and comfortable ones, lead to perdition.
http://agapienxristou.blogspot.ca/2013/04/path-to-heaven.html